In physics, motion is the phenomenon in which an object changes its position over time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and time. The motion of a body is observed by attaching a frame of reference to an observer and measuring the change in position of the body relative to that frame with change in time. The branch of physics describing the motion of objects without reference to its cause is kinematics; the branch studying forces and their effect on motion is dynamics.
If an object is not changing relatively to a given frame of reference, the object is said to be at rest, motionless, immobile, stationary, or to have a constant or time-invariant position with reference to its surroundings. As there is no absolute frame of reference, absolute motion cannot be determined. Thus, everything in the universe can be considered to be in motion.Motion applies to various physical systems: to objects, bodies, matter particles, matter fields, radiation, radiation fields, radiation particles, curvature, and space-time. One can also speak of motion of images, shapes, and boundaries. So, the term motion, in general, signifies a continuous change in the positions or configuration of a physical system in space. For example, one can talk about the motion of a wave or about the motion of a quantum particle, where the configuration consists of probabilities of occupying specific positions.
The main quantity that measures the motion of a body is momentum. An object's momentum increases with the object's mass and with its velocity. The total momentum of all objects in an isolated system (one not affected by external forces) does not change with time, as described by the law of conservation of momentum. An object's motion, and thus its momentum, cannot change unless a force acts on the body.
Hello!
I have this problem from an old exam I'm trying to solve. The problem is in Swedish so I've translated it:
NOTE that I accidentaly wrote $$C\neq 1$$ in the picture below. The correct problem statement is above.
But that part is not what I have problems with. The answer key says "if the...
So far I believe that speed changes during vertical circular motion, and its very hard to get uniform circular motion that is in the vertical plane.
This is because there is a difference in vertical height between the bottom/top of the circle so at the top the object must have done work against...
This question really troubles me.
Since we all know that the molecules are in perpetual random motion, why can't we make a perpetual motion machine by using molecular's always-moving energy??
I‘m a Grade 9 student and I'm unsure about this.
:doh::doh::doh:
Hello
I am trying to figure out the equations of motion for the following scenario: a mass m is held upright on by a massless rod mounted on a cart that is being pulled by a linear force. The caveat is that the rod is mounted on the cart via a torsional spring which causes a restorative torque...
Ok, so to start, the easy part, the velocity in the horizontal x direction (vx):
vx = 20m/(2.5s) = 8m/s
So far so good, but then for the vertical y velocity (vy), my answer is different than the book. I use the equation for position in the y direction, set the y value to 0 (the 2.5s it takes...
I thought the opposite should be true since its a general planar motion its not necessary that the magnitude of radius vector is constant so the change in direction and magnitude of radius vector should be generated by the perpendicular velocity vector and parallel velocity vector respectively ...
Now in determining the initial velocity;
in my understanding, if ##s=1.8## then we consider the stone's motion from the top to the ground. Why not consider ##s=3.6##, the total distance traveled by stone from start point ##t=0##? Is it possible to model equations from this point?
The stone...
Just looking for terminology here.
If an object moves through the solar system, what is the simplest terminology that relates to how the object moves through the solar system?
What are the words for if an object moves
towards the sun (radially inwards)
away from the sun (radially outwards)...
How does a polygon shaped body's toppling shifts from one edge to next adjacent edge when the object is already in motion without any sliding and no external force is applied ? Explain it with the case of hexagon or octagon both ways, with and without including CoM.
i solved it like this...
s = ut + 1/2 at^2
t= 1.08 (from part a)
u= 65 sin4.30
a= 9.81? or -9.81
the answer said -9.81
why? wouldn't acceleration change from -9.81 to +9.81 because it moves up then down???
its soo confusing...
So I thought the stone would initially experience acceleration in the backward (leftward) direction then continually accelerate in the inward direction of the tire (i.e. upward then rightward then downward then leftward, etc.) as the tire moves forward. But the answer is immediately upward...
TL;DR Summary: Problem said that the ball moves in a harmonic motion and asked to prove it. The process is adiabatic
Problem said that the ball moves in a harmonic motion and asked to prove it. The process is adiabatic.
I did the development, but at certain point I'm having a problem. The...
Problem: A small forest animal jumps with an initial speed of v0 = 15.0m/s and travels to a maximum height of 2.160m. What horizontal distance would the animal travel if the launch angle is i) 45.0 degrees or ii) 42.0 degrees?
Correct Answer: i) 24.95m ii) 25.02m
My professor solved this by...
I did this too fast idk if I'm wrong
So for the x component
use the formula d = rt / delta x = v*t
26 = vcos(theta)
y component
use the displacement formula
19.6 = vsin(theta)
tan^-1(19.6/26) = 36.5 degrees
the answer key says 20.2 degrees idk whats wrong
I am trying to understand the motion of the sphere in the image above, and I am a bit confused about the motion. How does the ball move down the cone? Will the rotation of the cone cause the ball to rotate with it, and which direction would the static friction be in? What does the path the ball...
so then when we model the velocity of the motion of a rocket (e.g., in a mathematics report), is it reasonable to assume that the initial velocity equals zero? I also apologise for my lack of information if I made a huge mistake in my question 🙏🏻
TL;DR Summary: Find initial vertically upward speed of the ball
Find horizontal speed of the speed
Find angle
How to:
Find initial vertically upward speed of the ball
Find horizontal speed of the speed
Find anglei try to solve it but it didn't work
TL;DR Summary: Find horizontal velocity?
I have no idea how to solve the problem, the question only provide distance 16cm(h),3.6cm(v) and acceleration = 0
What kind of lab activity would you use an Adjustable Hand Stroboscope for?
https://prolabscientific.com/Education-supplies/Physics/Force-and-motion/Stroboscopes/Hand-Stroboscope-Adjustable.html
Would it purely be a qualitative activity? I can't imagine you can do anything really quantitative...
I think it's not possible.
In 3D for constant acceleration we have : ##\vec v = \vec v_0 + \vec a t##
It's a line in 3 dimension so velocity's magnitude(speed) is changing with time.
I appreciate any better idea.
The question : A car and a truck are both traveling with a constant speed of 20 m/s. The car is 10 m behind the truck. The truck driver suddenly applies his brakes, causing the truck to slow to a stop at the constant rate of 2 m/s2. Two seconds later, the driver of the car applies their brakes...
The Alpha Experiment at CERN has finally produced a paper on whether antimatter falls towards the earth under gravity. The research confirms that antimatter acts identically to regular matter in regards to gravity.
Observation of the effect of gravity on the motion of antimatter. Anderson...
I don't undertand the equation. It is Newtons's second law of motion, so it decribes a force that acts on a single disc relative to the ground. So when the force is proportional to velocity, shouldn't it be ##-bv##? Because the dics's velocity is ##v## relative to the ground. Relative to the...
Dear Experts.
In a problem where we need to calculate the acceleration of a satellite in a force free space which sweeps and collects interplanetary dust and a certain rate (dm/dt), I believe that the equation F = m(dv/dt) + v(dm/dt) can be used, by putting F=0 and substituting the function...
Hello.
I have tried to solve it using x-t Graph. We know that period of this function is ##T=\frac {1}{6}s##.
Then I've used ##x(t)=0## to find the times in which the oscillator is at ##x=0##:
##t=\frac {k}{12} + \frac {1}{24}## for ## k \in Z.##
Now I can draw x-t graph.
We should check time...
I'm trying to design a mechanism to translate reciprocating motion into a 45 degree rotation.
Here's the idea:
A pin will push against the part marked in red, causing part of the desired rotation. Then, when the pin is pulled back, its interaction with the blue part will complete a 45 degree...
Thank you guys for taking the time to read this - I'm decently struggling with first year and need some tips on how to properly conceptualize problems and learn what the right approach is on certain problems.
Have a wonderful day, again thank you for checking this post out!
As the observer is moving, there will be a magnetic force.
Electric Field of the Rod = λ/2πεr r̂
Electric Force on the Point Charge = qλ/2πεr r̂
Magnetic Force on the Point Charge = q(vxB) = qvB n̂ = qv(µI/2πr) n̂ = qv(µλv/2πr) n̂
= µqλv²/2πr n̂
Total Force = Electric Force + Magnetic Force
We know that all actions are invariant under their gauge transformations. Are the equations of motion also invariant under the gauge transformations?
If yes, can you show a mathematical proof (instead of just saying in words)?
Hi I have come across something confusing in rolling motion. If an object moves with a positive V_cm meaning to the right its angular velocity will be clockwise or negative. The formula is V_cm=wR but for a positive V_cm you get a negative w as it moves clockwise if V_cm is to the right...
$$i \gamma^{\mu} \partial_{\mu} \psi = m \psi_c \\
i \gamma^{\mu} \partial_{\mu} \psi_c = m \psi
$$
Where ##\psi_c = C \gamma^0 \psi^*##
Show that the above equations can be obtained from the followong lagrangian
$$
L = \overline{\psi} i \gamma^{\mu} \partial_{\mu} \psi - \frac{1}{2} m \left...
I was reading about the Tusi couple and read it "as a solution for the latitudinal motion of the inferior planets, and later used extensively as a substitute for the equant". Since the Tusi couple is related to plotting out an ellipse, did Nasir al-Din al-Tusi already discover the laws for...
I believe I've solved this problem, however, I got through it pretty quickly and since it's the last problem on the assignment, I feel that I may have had an oversight.
For part a, I got: fs=md(α^2)(t^2)
and for part b, I got: ω=Sqrt((µs*g)/d)
Could someone confirm my answers? I've attached a...
For whatever reason, I'm having a hard time conceptualizing this problem. I understand that the tangential components of all forces involved need to cancel out in order for the bead to be stationary. I also understand that there is a mgsinθ in the negative θ-hat direction. What I don't...
In his thought experiment on the relativity of simultaneity, Einstein synchronizes two clocks A and B (at either end of a rod) to the clock C in a stationary frame, while A and B (the rod) is moving relative to C. The equations Einstein finishes with demonstrate how observers moving with A and...
I can't find the answer anywhere here's my question. can a centrifuge exist outside a field of gravity. More specifically, in a theoretical void of nothing without stars in view or any point of reference for comparison how could motion like spinning or acceleration exist?
Is it possible, that one physics law is "Everything is in motion?" (since zero doesnt belong to nature)...if so, does that implies that black holes move?
A recurring question is: while the motion of a polar Foucault pendulum is fairly straightforward, the case of a non-polar Foucault pendulum is quite difficult to visualize.
In 2020, on physics stackexchange someone submitted that question and I contributed an answer.
In a comment to another...
I'll risk a quick off-topic answer here, since I think it's straightforward QM, not vague "interpretation" stuff. :oldbiggrin:
In QM (e.g., Ballentine p81), for a free particle, ##H = \frac12 \, M\, V\cdot V + E_0##. So in the ground state ##|E_0\rangle## we have ##H|E_0\rangle = E_0...
TL;DR Summary: Prove that a sum of trigonometric ratios is periodic but not not simple harmonic.
We need to prove that ##x = sin{\omega t} + sin{2\omega t} + sin{4\omega t}## where ##x## is the displacement from the equilibrium position at time ##t##.
I can see that each term is a SHM, but...